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Isingeniso sePolyolefins kanye neFilimu Extrusion

I-Polyolefins, ikilasi lezinto ezisetshenziswayo ze-macromolecular ezihlanganiswe kusuka kuma-olefin monomers njenge-ethylene ne-propylene, angamapulasitiki akhiqizwa futhi asetshenziswa kakhulu emhlabeni jikelele. Ukusabalala kwazo kubangelwa inhlanganisela yezakhiwo ezingavamile, okuhlanganisa izindleko eziphansi, ukucutshungulwa okuhle kakhulu, ukuzinza okuvelele kwamakhemikhali, nezici zomzimba ezihambisanayo. Phakathi kokusetshenziswa okuhlukahlukene kwe-polyolefin, imikhiqizo yefilimu ibamba isikhundla esiphezulu, isebenza imisebenzi ebalulekile ekufakweni kokudla, ukumbozwa kwezolimo, ukupakishwa kwezimboni, imikhiqizo yezokwelapha nenhlanzeko, kanye nezimpahla zansuku zonke zabathengi. Izinsalela ze-polyolefin ezivame kakhulu ezisetshenziselwa ukukhiqizwa kwefilimu zihlanganisa i-polyethylene (PE) - ehlanganisa i-Linear Low-Density Polyethylene (LLDPE), i-Low-Density Polyethylene (LDPE), ne-High-Density Polyethylene (HDPE) - ne-polypropylene (PP).

Ukwenziwa kwamafilimu e-polyolefin ngokuyinhloko kuncike kubuchwepheshe be-extrusion, ne-Blown Film Extrusion ne-Cast Film Extrusion okuyizinqubo ezimbili ezibalulekile.

1. Inqubo ye-Blown Film Extrusion

I-Blown film extrusion ingenye yezindlela ezivame kakhulu zokukhiqiza amafilimu e-polyolefin. Umgomo oyisisekelo ubandakanya ukukhipha ipholimeri encibilikisiwe iye phezulu iye phezulu ngokusebenzisa i-annular die, ukwakha i-parison ye-tubular enezindonga ezincane. Kamuva, umoya ocindezelwe ungeniswa ngaphakathi kuleli sonto, okubangela ukuthi ugcwale ube yibhamuza elinobubanzi obukhulu kakhulu kunalelo lefasitela. Njengoba ibhamuza likhuphuka, lipholiswa ngenkani futhi liqiniswe yindandatho yomoya yangaphandle. Ibhamuza elipholile libe seligoqwa isethi yama-nip roller (ngokuvamile kusetshenziswa ifremu egoqayo noma i-A-frame) bese lidonswa amarola okudonsa ngaphambi kokuba alinyathele kumqulu. Inqubo yefilimu evunguzayo ivamise ukukhiqiza amafilimu anomumo we-biaxial, okusho ukuthi abonisa ibhalansi enhle yezakhiwo zomshini kuzo zombili isiqondiso somshini (MD) kanye nesiqondiso esiphambene (TD), njengamandla aqinile, ukumelana nezinyembezi, namandla okuthinta. Ubukhulu befilimu kanye nezakhiwo zemishini zingalawulwa ngokulungisa isilinganiso sokuqhunyiswa (i-BUR - isilinganiso se-bubble diameter kuya ku-die diameter) kanye ne-draw-down ratio (DDR - isilinganiso sejubane lokuthatha ukuya kusivinini sokuphuma).

2. Inqubo ye-Cast Film Extrusion

I-Cast film extrusion ingenye inqubo ebalulekile yokukhiqiza amafilimu e-polyolefin, afanele ikakhulukazi ukukhiqiza amafilimu adinga izici zokukhanya eziphakeme (isb., ukucaca okuphezulu, ukucwebezela okuphezulu) nokufana okuhle kakhulu kogqinsi. Kule nqubo, i-polymer encibilikisiwe ikhishwa ngokuvundlile ngokusebenzisa i-T-die eyisicaba, i-slot-type, yakhe iwebhu encibilikisiwe efanayo. Le webhu ibe isidonswa ngokushesha endaweni eyodwa noma ngaphezulu, i-chill rolls epholile ngaphakathi enesivinini esikhulu. Ukuncibilika kuqina ngokushesha lapho kuthinta indawo ebandayo. Amafilimu e-Cast ngokuvamile anezakhiwo ezinhle kakhulu zokubona, ukuzwa okuthambile, kanye nokuvala ukushisa okuhle. Ukulawula okunembile kwegebe lezindebe ezifayo, izinga lokushisa le-chill roll, nesivinini sokuzungeza kuvumela ukulawulwa okunembile kokuqina kwefilimu nekhwalithi yendawo.

Izinselele ezi-6 eziphezulu ze-Polyolefin Extrusion Film

Ngaphandle kokuvuthwa kobuchwepheshe be-extrusion, abakhiqizi bavame ukuhlangana nochungechunge lobunzima bokucubungula ekukhiqizeni amafilimu e-polyolefin, ikakhulukazi lapho belwela ukukhipha okuphezulu, ukusebenza kahle, amageji amancane, nalapho besebenzisa ama-resin amasha asebenza kahle kakhulu. Lezi zinkinga azithinti nje kuphela ukuzinza kokukhiqiza kodwa ziphinde zibe nomthelela oqondile kwikhwalithi yomkhiqizo wokugcina kanye nezindleko. Izinselelo ezibalulekile zifaka:

1. I-Melt Fracture (Sharkskin): Lokhu kungenye yeziphambeko ezivame kakhulu ku-polyolefin ifilimu extrusion. Ngokwe-Macroscopically, ibonakala njengama-ripples aguquguqukayo ngezikhathi ezithile noma indawo embi ngendlela engavamile kufilimu, noma ezimeni ezinzima, ukuhlanekezela okubonakala kakhudlwana. Ukuqhekeka kwe-Melt kwenzeka ngokuyinhloko lapho izinga le-shear le-polymer encibilika ephuma ku-die lidlula inani elibucayi, okuholela ekugubheni kwe-stick-slip oscillations phakathi kodonga lokufa kanye nokuncibilika kwenqwaba, noma lapho ukucindezeleka okunwetshiwe ekuphumeni kokufa kudlula amandla okuncibilika. Lesi sici silimaza kakhulu izici zefilimu zokubona (ukucaca, ukucwebezela), ubushelelezi bendawo, futhi kungehlisa isithunzi izici zayo zokusebenzisa kanye nezithiyo.

2. I-Die Drool / I-Die Build-up: Lokhu kubhekisela ekuqoqweni kancane kancane kwemikhiqizo yokuwohloka kwe-polymer, izingxenyana zesisindo samangqamuzana aphansi, izithasiselo ezingahlakazeki kahle (isb., ama-pigments, ama-antistatic agents, ama-slip agents), noma ama-gel avela ku-resin emaphethelweni e-die lip noma ngaphakathi kwendawo yokufa. Lawa madiphozithi angakwazi ukuhlehla ngesikhathi sokukhiqiza, angcolise indawo yefilimu futhi abangele ukonakala okufana namajeli, ama-streaks, noma imihuzuko, ngaleyo ndlela kuthinte ukubukeka nekhwalithi yomkhiqizo. Ezimweni ezimbi kakhulu, ukwakheka kwefa kungavimba indlela ephumayo, okuholela ekuhlukeni kwegeji, ukuklebhuka kwefilimu, futhi ekugcineni kuphoqe ukuvalwa kolayini wokukhiqiza ukuze kuhlanzwe ukufa, okuholela ekulahlekelweni okukhulu ekusebenzeni kahle kokukhiqiza kanye nokumoshwa kwempahla eluhlaza.

3. I-High Extrusion Pressure and Fluctuation: Ngaphansi kwezimo ezithile, ikakhulukazi lapho ucubungula ama-resin e-viscosity ephezulu noma usebenzisa izikhala ezincane zokufa, ingcindezi engaphakathi kwesistimu ye-extrusion (ikakhulukazi ekhanda le-extruder kanye nokufa) ingaba phezulu kakhulu. Ukucindezela okuphezulu akukhulisi ukusetshenziswa kwamandla kuphela kodwa futhi kubangela ingozi yokuphila isikhathi eside kwemishini (isb., isikulufu, umgqomo, ukufa) nokuphepha. Ngaphezu kwalokho, ukuguquguquka okungazinzile kwengcindezi ye-extrusion kubangela ngokuqondile ukuhluka kokuncibilika kokuncibilika, okuholela ekushubeni kwefilimu engalingani.

4. Ukusebenza Okunomkhawulo: Ukuze kuvinjwe noma kuncishiswe izinkinga ezifana nokuncibilika kokuncibilika kanye nokwakheka kwefa, abakhiqizi bavame ukuphoqeleka ukuthi banciphise isivinini sesikulufu se-extruder, ngaleyo ndlela banciphise okukhiphayo kolayini wokukhiqiza. Lokhu kuthinta ngokuqondile ukusebenza kahle kokukhiqiza kanye nezindleko zokukhiqiza ngeyunithi ngayinye yomkhiqizo, okwenza kube nzima ukuhlangabezana nezidingo zemakethe zamafilimu amakhulu, abiza kancane.

5. Ubunzima bokulawula i-Gauge: Ukungazinzi ekuncibilikeni kokuncibilika, ukusatshalaliswa kwezinga lokushisa okungajwayelekile kulo lonke idayizi, kanye nokwakheka kwefasi kungaba nomthelela ekuhlukeni kogqinsi lwefilimu, kokubili ngokuphambana nangobude. Lokhu kuthinta ukusebenza kwefilimu okulandelayo nezici zokusetshenziswa ekugcineni.

6. Ukushintsha Ukushintsha Kwenhlaka Enzima: Lapho ushintsha phakathi kwezinhlobo ezihlukene noma amabanga ama-polyolefin resins, noma lapho ushintsha ama-masterbatches ombala, impahla eyinsalela kusukela ekugijimeni kwangaphambilini ngokuvamile kunzima ukuyikhipha ngokuphelele ku-extruder futhi ife. Lokhu kuholela ekuhlanganisweni kwezinto ezindala nezintsha, ukukhiqiza izinto eziguqukayo, ukwandise izikhathi zokushintsha, nokwenyuka kwamazinga okulahlwa.

Lezi zinselele ezivamile zokucubungula zicindezela imizamo yabakhiqizi bamafilimu e-polyolefin yokuthuthukisa ikhwalithi yomkhiqizo nokusebenza kahle kokukhiqizwa, futhi zibeka imigoqo ekwamukelweni kwezinto ezintsha nezindlela zokucubungula ezithuthukile. Ngakho-ke, ukufuna izixazululo ezisebenzayo zokunqoba lezi zinselele kubalulekile ekuthuthukisweni okusimeme nokunempilo kwayo yonke imboni yefilimu ye-polyolefin extrusion.

Izixazululo Zenqubo Yokukhipha Ifilimu Ye-Polyolefin: I-Polymer Processing Aids (PPAs)

I-Polymer Processing Aids (i-PPAs) iyizithasiselo ezisebenzayo inani layo eliyisisekelo lilele ekuthuthukiseni ukuziphatha kwe-rheological kwe-polymer encibilikayo ngesikhathi sokukhipha futhi iguqule ukusebenzisana kwayo nezindawo zemishini, ngaleyo ndlela inqobe uchungechunge lobunzima bokucubungula futhi ithuthukise ukusebenza kahle kokukhiqiza kanye nekhwalithi yomkhiqizo.

1. Ama-PPA asekelwe ku-Fluoropolymer

Isakhiwo Sekhemikhali kanye Nezimpawu: Lezi okwamanje yizigaba ezisetshenziswa kakhulu, ezivuthiwe ngokobuchwepheshe, futhi ezibonakala zisebenza kahle kakhulu zama-PPA. Ngokuvamile ama-homopolymer noma ama-copolymer asekelwe kuma-fluoroolefin monomers afana ne-vinylidene fluoride (VDF), i-hexafluoropropylene (HFP), kanye ne-tetrafluoroethylene (TFE), kanye nama-fluoroelastomers amelela kakhulu. Amaketanga wamangqamuzana alawa ma-PPA anothile ngamabhondi e-CF anesibopho esikhulu, ane-polarity ephansi ye-CF, anikeza izici ze-physicochemical eziyingqayizivele: amandla angaphezulu aphansi kakhulu (okufana ne-polytetrafluoroethylene/Teflon®), ukuzinza okuhle kakhulu okushisayo, nokungangeni kwamakhemikhali. Ngokubalulekile, ama-PPA e-fluoropolymer ngokuvamile abonisa ukungahambisani kahle namatrices we-polyolefin angeyona i-polar (njenge-PE, PP). Lokhu kungahambisani kuyisidingo esibalulekile sokuthuthela kwabo okusebenzayo endaweni yensimbi ye-die, lapho benza khona i-lubricating coating eguqukayo.

Imikhiqizo Emele abanye: Imikhiqizo ehamba phambili emakethe yomhlaba wonke yama-fluoropolymer PPAs ihlanganisa uchungechunge lwe-Chemours' Viton™ FreeFlow™ kanye nochungechunge lwe-3M's Dynamar™, olulawula isabelo semakethe esibalulekile. Ukwengeza, amamaki athile e-fluoropolymer asuka ku-Arkema (uchungechunge lwe-Kynar®) kanye ne-Solvay (Tecnoflon®) nawo asetshenziswa njenge, noma izingxenye eziyinhloko, ekwakhiweni kwe-PPA.

2. I-Silicone-based Processing Aids (PPAs)

Isakhiwo Sekhemikhali kanye Nezimpawu: Izingxenye eziyinhloko ezisebenzayo kuleli klasi lama-PPA ama-polysiloxanes, avame ukubizwa ngokuthi ama-silicone. Umgogodla we-polysiloxane uqukethe i-silicon nama-athomu oksijini (-Si-O-), namaqembu e-organic (imvamisa i-methyl) enamathiselwe kuma-athomu e-silicon. Lesi sakhiwo samangqamuzana esiyingqayizivele sinikeza izinto ze-silicone ezinobunzima obuphansi kakhulu, ukuqina okuhle kakhulu kokushisa, ukuguquguquka okuhle, kanye nezakhiwo ezinganamatheli ezintweni eziningi. Ngokufanayo nama-PPA e-fluoropolymer, ama-PPA asekelwe ku-silicone asebenza ngokuthuthela endaweni yensimbi yezinto zokucubungula ukuze akhe isendlalelo sokuthambisa.

Izici Zohlelo Lokusebenza: Nakuba ama-PPA e-fluoropolymer ebusa umkhakha wefilimu we-polyolefin extrusion, ama-PPA asekelwe ku-silicone angase abonise izinzuzo eziyingqayizivele noma adale imiphumela ye-synergistic uma esetshenziswa ezimweni ezithile zohlelo lokusebenza noma ngokuhambisana nezinhlelo ezithile ze-resin. Isibonelo, zingase zicatshangelwe izinhlelo zokusebenza ezidinga ama-coefficient aphansi kakhulu okungqubuzana noma lapho kufunwa khona izici ezithile zendawo zomkhiqizo wokugcina.

Ubhekene Nokuvinjelwa Kwe-Fluoropolymer noma Izinselele Zokuhlinzeka Nge-PTFE?

Xazulula Izinselele Zokunwetshwa Kwefilimu Ye-Polyolefin Nge-PFAS-Free PPA Solutions-Izithasiselo ze-Fluorine zamahhala ze-SILIKE ze-Polymer

I-SILIKE ithatha indlela esheshayo ngemikhiqizo yayo yochungechunge lwe-SILIMER, ehlinzeka ngokusungulwayoIzinsiza zokucubungula ze-polymer zamahhala ze-PFAS (ama-PPAs). Lo mugqa womkhiqizo ophelele uhlanganisa ama-PPA angenawo ama-PFAS angama-100%,Izithasiselo ze-PPA Polymer ezingena-fluorine, futhiI-PFAS-free & fluorine-free PPA masterbatches.Ngoukuqeda isidingo sezithasiselo ze-fluorine, lezi zinsiza zokucubungula zithuthukisa kakhulu inqubo yokukhiqiza ye-LLDPE, i-LDPE, i-HDPE, i-mLLDPE, i-PP, nezinqubo ezihlukahlukene ze-polyolefin extrusion yefilimu. Zihambisana nemithetho yakamuva yezemvelo kuyilapho zithuthukisa ukusebenza kahle kokukhiqiza, ukunciphisa isikhathi sokuphumula, nokuthuthukisa ikhwalithi yomkhiqizo iyonke. Ama-PPA angenayo i-PFAS ka-SILIKE aletha izinzuzo emkhiqizweni wokugcina, okuhlanganisa ukuqedwa kokuqhekeka kwe-ncibilika (isikhumba sikashaka), ukushelela okuthuthukisiwe, kanye nekhwalithi ephezulu yendawo.

Uma ulwa nomthelela wokuvinjelwa kwe-fluoropolymer noma ukushoda kwe-PTFE ezinqubweni zakho ze-polymer extrusion, i-SILIKE inikezaezinye izindlela esikhundleni se-fluoropolymer PPAs/PTFE, Izithasiselo zamahhala ze-PFAS zokwenziwa kwefilimuezenzelwe ukuhlangabezana nezidingo zakho, ngaphandle koshintsho lwenqubo oludingekayo.